Sets of chairs



July 12, 1955 A. WIRTH 2,712,848

SETS OF CHAIRS Filed Opt. 16, 1951 3 Sheets-Sheet 1 July 12, 1955 A. WIRTH 2,712,848

SETS OF CHAIRS Filed Oct. 16, 1951 5 Sheets-Sheet 2 July 12, 1955 A. WIRTH 2,712,848

SETS 0F CHAIRS Filed Oct. 16, 1951 3 SheetsSheet 5 United States Patent SETS 825 CHAIRS Armin Wirth, Zurich, Switzerland Appiication @ctober 16, 1951, Serial No. 251,469

12 Claims. {C 155-2) This invention relates to a chair of simple and solid construction which is so designed as to enable it to be nested with other similar chairs with extremely small additional space requirement for every additional chair.

An object of the invention is to provide a chair of the type indicated which has a rigid frame without any parts to be folded in order to enable nesting of the chair with other similar chairs.

Another object of the invention is to provide a chair of the type indicated which can readily be coupled sideways to other similar chairs to form a substantially rigid unit of interconnected chairs.

A further object of the invention is to provide means for rigidly connecting a plurality of chairs of the type indicated sideways in such a way as to provide a limited adjustability of said row of chairs to slight unevenness of the ground or fioor without disturbing the lateral relation of the chairs.

Cther ob iccts and advantages of the invention will be evident from the following description with reference to the accompan 'ing drawings, in which:

Fig. l is a plan view of an embodiment of the chair with the back rest and the seat shown in dotted lines,

Fig. 2 is a side elevation of said chair with its seat in raised position and with a second nested chair shown in dotted lines,

Fig. 3 is a front elevation of a chair frame with a raised seat and the back rest shown in dotted lines.

Figs. 4, 5 and 6 show details of the chair, Fig. 4 being an elevation, while Figs. 5 and 6 are cross sections,

Figs. 7 and 8 are detail views showing the attachment of the back rest to the chair frame,

Figs. 9, 1i) and 11 are similar detail views showing the hinged connection between the seat and the chair frame, and

Fig. 12 is a perspective view showing two nested chairs.

In the embodiment shown in the drawings, the chair comprises a rigid frame consisting of a rear substantially U-shaped element 5, 31, i5 and side elements 9, 10, i2, 13, 14 which project forwardly from the lower part of the rear element 11, 15, one at each side thereof. The two side elements are joined at their rear upper part by a transverse member 3 integral with said side elements.

The rear substantially U-shaped element includes a ground engaging horizontal member 15, from the ends of which two parallel members 11 proiect upwards with a forward inclination, as shown in Fig. 2, each of said members 11 being provided at its upper end with an extension member 5 which is inclined backwards.

Each side element is a substantially horizontal ground engaging member 13 continuing at its rear end with an inclined member 12 which at its rear end has a depending member 20 parallel with the members At its front end, the member 13 is bent upwards to form an upright member 14 which, in turn, continues in rearwardly directed members 9, it ioined at the rear end of the and the nut 25 is preferably a cap nut.

member 10 by an upwards directed member 19 which is parallel with the members 5 of the rear element of the chair frame. The transverse member 8 joins the upper ends of the members 19.

The members 19 and 20 are secured to the members 5 and 11, respectively, by means which are identical and, therefore, shown and described in detail in connection with the members 11 and 20 only (see Figs. 4-6).

An endless strip 18 snugly surrounds the members 11 and 2b, as shown in Figs. 5 and 6. in the embodiment of Fig. 5, the members 11, 20 are each provided with a transverse recess in the sides thereof facing each other, and said recesses are engaged by a pin 21 extending through holes in opposite sides of said strip 18. The pin 21 is tapered and forced into said recesses through one of the holes, so as to firmly press the members 11, 29 against the end portions of the strip 18. Obviously, this structure positively prevents relative displacement of the members 13. and 2t? in the direction of their longitudinal axes, as well as pivotal movement around said axes.

In the embodiment shown in Fig. 6, a spacer element 23 is provided between the members 11 and 2th. Said spacer element 23 is confined within the strip 18 and provided with side recesses snugly fitting the members 11 and 20. In order to prevent relative displacement of the members 11 and 2% within the strip 18, the parts are preferably secured to each o her by means of artificial resin cement, by soldering, or by zinc coating. In connection with certain materials, such as aluminum alloys, this can be accomplished simultaneously with hardening of said materials. Obviously, the above described structure provides a rigid and stable frame with substantial ground elements.

The chair is provided with a back rest which will now be described with reference to Figs. 2, 7, and 8. The back rest consists of a thin sheet 4 of a flexible material, such as plywood. Angle members 26 are secured to the sheet 4, preferably two at each end thereof, as indicated in Fig. 2.

Each angle member 26 is secured to the sheet 4 by means of a screw 2 with a nut 25. The screw 24 has a smooth head on the front side of the sheet 4 and extends through the sheet 4 and the member 26, On the side of the member 26 engagin the sheet 4, ridge shaped projections 27 are provided which cut into the sheet 4 and prevent pivotal displacement of the member 26.

The angle member 26 is provided with a pin 28 projecting into a recess 29 in the frame members 5, the shape and dimension of said pin 28 being such as to permit considerable freedom of movement of the pin 23 in the recess 29. The arrangement leaves a very small space 3%) between the member 5 and the cap nut 25 which prevents withdrawal of the pin 28 from the recess 29. The freedom of movement of the pins 28 in the recesses 29 permits free flexing of the back rest 4, for example as indicated by broken lines in Fig. 7, without undue stress on the parts. The fastening structure also permits such flexing of the upper part of the back rest 4 practically independently of the lower part thereof, and vice versa. Although not shown in the drawings, the members 5 are preferably bent slightly in the direction from each other at their upper portions,

so as to provide a slight pressure against the angle members 26.

The seat 1 consists of a thin sheet of a suitable material and has a front portion 2, which is bent downwards, and a rear portion 3 which is bent upwards as indicated in Fig. 2. The seat 1 is pivotally connected with the frame member 8 by means of a hinge device secured to the seat on the underside of the portion 3.

This hinge device will now be described with reference to Figs. 2, 9, 10, and 11.

Two hinge members 33 and 34 adapted to surround the member 8, as indicated in Fig. 9,'are secured to each other and to the seat portion 3 by means of a screw 31' with a nut 32. The screw 31 has a smooth head on the top side of the seat 1, and the hinge member 34 is provided with ridge shaped projections 35 on the .side thereof engaging the seat 1. These projections 35 cut into the seat material and prevent pivotal displacement of the hinge members.

The hinge members 33, 34 are positively located in relation to each other by interfitting portions thereof, as at 37, and formed with a recess 36 between them, said recess 36 accommodating the end portion 40 of a torsion spring 39 having a bent portion 43 and having its other end 39a secured in a hole 3% in the member 8.

A latch member 41 is provided on an extension 42 of the nut 32 and clamped against the hinge member 33 by means of said nut 32. Said latch member 41 is provided with an elongated slot so as to enable it to be. clamped either in the position shown in full lines' in Fig. 10, or in the position shown in dotted lines in said figure. When clamped in the first-mentioned posi tion, it is in engagement with the bent spring portion 43 with its right hand edge as indicated in Fig. 9 and with this arrangement, the spring 39 urges the seat 1 to its raised position. When the latch member 41 is clamped in the position indicated by dotted lines in Fig. 10, said latch member 41 is out of engagement with the spring and consequently the seat 1 is free to occupy any position independently of the spring 39.

The latch member 41 can also be secured in the position shown in full lines in Fig. 10 but with the bent portion .43 of the spring located at the opposite side of said latch member 41, i. e., in the position indicated at 44 in Fig. 9. With this arrangement the seat 1 is urged by the spring away from its raised position.

The hinge member 33 is provided with a recess 33a in which a lubrication'pad may be disposed in engagement with'the frame member 8.

The principal advantage of the present invention is that it enables a number of chairs to be readily nested together with very little additional space requirement for each chair added. As shown in Fig. 2, the seat 1 fits snugly against the back rest 4 in the raised position of the seat 1, and in this position the bent seat portion 2 extends above the upper end of the frame members so as to enable another chair to be placed with the frame members 5 in engagement with the underside of the raised seat 1 without interference from the seat portion 2, the front edge of which is then located slightly behind the backrest 4 of the front chair.

In order to enable such nesting of the chairs certain characteristics of the side elements 9, it), 12, 13, 14 are essential. As seen particularly in Fig. l, the members 9 and 13 of said side elements are bent outwards from the center line x of the chair. The bending point between the members 12 and 13 intbis horizontal direction is located a distance 7b behind the bending point between said members 12 and 13 in a vertical direction (see Figs. 1 and 2). The horizontal and vertical bends between the members 9 and it have a similar interrelation.

With this structure, when two or more chairs are nested (Figs. 2 and 12), the members 9 and 13 lie parallel beside each other while the members and 12 are disposed practically above and below each other, thus enabling the chairs to be nested closely as indicated above.

Modifications of the details of the described embodiment are feasible within the scope of the invention.

What I claim is:

1. In a chair, two side frames, a rear frame, means connecting said side frames to said rear frame to form a rigid unit in which the sole connection between the side frames and the rear frame is at said rear frame, a foldable seat, and a back rest secured to said rear frame, the front portions of said side frames converging rearwardly in a horizontal plane and forming ground engaging and seat supporting elements, while the rear portions of said side frames converge rearwardly in a vertical plane. 9 i Y 2. In a chair, two side frames, a rear frame, means connecting said side frames to. said near frame to form a rigid frame unit in which the sole connection between said side frames and said rear frame is at said rear frame, a back rest secured to said rear frame, and a foldable seat which, in its raised position, snugly engages a substantial area of said back rest, the front portions of said side frames converging rearwardly in a horizontal plane and forming ground engaging and seat supporting elements, while the rear'portions of said side frames converge rearwardly in a vertical plane.

3. In a chair, two side frames, a rear frame, means connecting said side frames to said rear frame to form a rigid frame unit in which the sole connection between said side frames and said rear frame is at said rear frame, upwardly directed extensions on said rear frame, a flexible normally flat back rest hingedly secured to said extensions, and a foldable seat which, in its raised position, snugly engages a substantial area of said back rest, the front portions of said side frames converging rearwardly in a horizontal plane and forming ground engaging and seat supporting elements, while the rear portions of said side frames converge rearwardly in a vertical plane.

4. A chair as set forth in claim 3, in which said means pivotally connecting the back rest to said. extensions comprise angle members, means securing said angle members to said back rest, projections on said angle members, and recesses in said extensions accommodating said projections with limited freedom of movement.

5. A chair as set forth in claim 4, in which said recesses are disposed in opposite outer sides of said' extensions.

6. A chair as set forth in claim 3, in which said means pivotally connecting the back rest to the rear frame comprise angle members, means securing said angle members to said back rest, projections on said angle members,

recesses in said extensions accommodating said projections with limited freedom of movement said recesses being disposed in opposite outer sides of said extensions, and lugs on said means securing the angle members to the back rest, said lugs being disposed in a position to prevent withdrawal of said projections from said recesses.

7. in a chair, two side frames, a rear frame having a ground engaging element, means connecting said side frames to said rear frame to form a rigid frame unit in which the sole connection between said side frames and said rear frame is at said rear frame, upwardly vdirected extensions on said'rear frame, a flexible normally flat back rest hingedly secured to said extensions, and a foldable seat which, in its raised position, snugly engages a substantial area of said back rest, the front portions of said side frames converging rearwardly in a horizontal plane and forming ground engaging and seat supporting elements, while the rear portions of said side frames converge rearwardly in a vertical plane.

8. A chair as set forth in claim 7, in which said means rigidly connecting said rear frame with said side frames comprise endless strips surrounding parallel members of said frames, a spacer between said parallel members within each of said strips, and means securing said members, said strip, and said spacer together.

9. In a chair, two side frames, a rear frame, said side frames having elements at the rear end thereof extending parallel to said rear frame, an endless strip surrounding each of said elements and the adjacent portion of said rear frame, a hole in said strip, a wedge extending through said hole between said parallel members to force them apart against the inner surface of said endless strip, whereby to form a rigid unit from said frames in which the sole connection between the side frames and the rear frame is at said rear frame, a foldable seat, and a back rest secured to said rear frame, the front portions of said side frames converging rearwardly in a horizontal plane and forming ground engaging and seat supporting elements, while the rear portions of said side frames converge rearwardly in a vertical plane.

10. A chair as set forth in claim 9, in which said parallel members are provided with registering transverse recesses for receipt of said wedge.

11. In a chair, two side frames, a rear frame, means connecting said side frames to said rear frame to form a rigid unit in which the sole connection between the side frames and the rear frame is at said rear frame, a horizontal frame member at said rear frame, a seat, hinge means pivotally connecting said seat to said horizontal frame member, spring means secured to said horizontal frame member, adjustable means associated with said hinge means to selectively bias said spring means to urge said seat in either direction, and a back rest secured to said rear frame, the front portions of said side frames converging rearwardly in a horizontal plane and forming ground engaging and seat supporting elements, While the rear portions of said side frames converge rearwardly in a vertical plane,

12. A chair as set forth in claim 11, including a Inbricant pad in said hinge members in engagement with said horizontal member.

References Cited in the file of this patent UNITED STATES PATENTS 1,196,614 Teipel Aug. 29, 1916 1,922,582 Goodrich Aug. 15, 1933 1,934,396 Bales Nov. 7, 1933 1,941,340 Dellert Dec. 26, 1933 2,061,235 Horn Nov. 17, 1936 2,146,932 Boman Feb. 14, 1939 2,174,224 Geller Sept. 26, 1939 2,578,397 Brown Dec. 11, 1951 FOREIGN PATENTS 149,818 Austria June 10, 1937 152,786 Austria Mar. 10, 1938 478,756 Great Britain Jan. 25, 1938 638,847 Great Britain June 14, 1950 

